Offset layout apparatus



June 6, 1967 R. s. HAYNIE OFFSET LAYOUT APPARATUS 2 Sheets-Sheet 1 Filed Jan. 28, 1966 Robert S. Haynie INVENTOR.

June 6, 1967 R. S. HAYNIE OFFSET LAYOUT APPARATUS 2 Sheets-Sheet 2 Filed Jan. 28, 1966 Robert S. Haynie 1 N VL N TOR a Anarneys United States Patent 3,323,212 OFFSET LAY OUT APPARATUS Robert S. Haynie, 703 Gary Sta, Augusta, Ga. 30904 Filed Jan. 28, 1965, Ser. No. 523,773 6 Claims. (Cl. 33-27) This invention relates generally to sheet metal offset layout apparatus, and more specifically to apparatus for enabling .so-called streamline offsets to be quickly, ac curately and readily laid out on sheet metal blanks.

Air used for heating and cooling is normally conveyed through pipes called ducts. These heating and cooling ducts for circulating air usually require at least one or more direction changing or sidestepping sections therein to direct the ducts either vertically or horizontally about obstacles. When these sections sidestep less than three or four feet of offset distance, duct sections termed in the prior art either straight-S or streamlined offsets are used.

These streamlined offsets comprise four-sided duct sections, the upper and lower walls of which are flat and yet cut out in the configuration of a gentle curve and the two sides are bent to match the curved top and bottom wall. In the past these top and bottom walls were laid out by a sheet metal mechanic using a trial and error or triangulation method. The layout, by this method, proved to he usually inaccurate, requiring sketching in at the cutout edges of over and under cuts, as well as a good deal of leftover scrap metal. Further, this method of layout required approximately ten to twenty minutes per offset for the simplest form of offset, depending upon the skill of the mechanic, and normally necessitated the use of a full sheet or blank of sheet metal and the entire working surface of a layout table. There are several types of offsets which by usual layout procedures requires up to forty-five minutes to layout and which may be done using my invention in five minutes or less.

Accordingly, this invention prov-ides means for quickly and extremely accurately laying out and inscribing or marking streamlined offsets in sheet metal blanks, obviat ing the major defects of the layout methods used in prior art. Briefly, this invention is based on the novel concept of automatically determining the radius of curvature of the centerline of a predetermined streamlined offset, the determination being dependent upon three variables, the length of the offset, the width of the offset, and the amount of offset desired. This determination is utilized or made effective by the provision of a plurality of calibrated bars having a preset pattern of holes therein, the bars corresponding to the variable of offset length and the holes corresponding to the variable of the amount of offset. The invention preferably comprises an attachment for mounting on a conventional sheet metal layout table including means for accurately positioning the sheet metal blank on the table to ensure that the proper width of the cutout offset will be inscribed. That is, a third vari able, the width of offset is taken care of by the table attachment. The attachment also includes means for providing a joining allowance on the length of the offset, this means comprising an adjustable depth gauge on the positioning means.

Accordingly, it is an object of the present invention to provide novel and unique means for accurately, rapidly and automatically determining, laying out and inscribing streamlined offsets in sheet metal blanks.

Another object of the present invention is to provide offset layout apparatus which reduces lost or scrap metal when laying out offset, allowing the use of small blanks rather than the usual large blanks necessary for laying out an offset as done in the prior art, and providing for extremely accurate streamlined offsets as an end result.

It is another object of the present invention to pr vide an attachment means for use on a layout table for accurately indicating the position of sheet metal blanks on the table in order to lay out streamlined offsets therein, the indication being dependent upon the desired width of the offset.

It is a further object of the present invention to provide a semi-automatic offset layout apparatus for de termining and inscribing the edges of a streamlined offset on a sheet metal blank.

It is another object of the present invention to provide apparatus of the character desciibed which is ineXpensive, which may be easily constructed out of readily available materials, which is sturdy and trouble-free in op eration, and which is extremely accurate when used for its intended purpose.

It is a further object of the present invention to provide novel inscribing tools for use with. the offset layout apparatus of the present invention, the tools allowing for the marking off or inscribing of both edges of an offset at the same time.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like part throughout, and in which:

FIGURE 1 is a partial top plan view of a layout table having the offset layout apparatus comprising the present invention mounted in place thereon;

FIGURE 2 is an enlarged partial vertical sectional view of the layout ta be illustrated in FIGURE 1 taken on the plane of the line 22 of FIGURE 1;

FIGURE 3 is a partial exploded perspective view of the table mounting attachment comprising a portion of the present invention;

FIGURE 4- is a partial perspective view, also partially in cross-section, illustrating the depth gauge comprising a portion of the present invention; and

FIGURES 5 and 6 are perspective views of the first and second marking heads used with the apparatus illustrated in FIGURES l and 2.

Referring now more specifically to the drawings, reference numeral 10 is used to generally denote a layout table of the usual conventional variety including the top or sheet metal receiving surface 12 for receiving blanks of sheet metal such as blank 14 thereon. It will be understood, of course, that the layout table ltl is a conventional table as used in the general sheet metal layout shop in which the prior art method of triangulation is used for laying out streamlined offsets in sheet metal. However, as conventionally used, the entire surface of the top 12 would be required in order to lay out one offset such as that generally denoted by reference numeral 16, in which the letter W is used to indicate the width of the offset, the letters OS are used to denote the offset distance and the letter L is used to denote the length of the offset.

The offset layout apparatus used in conjunction with the table 10 for automatically laying out and inscribing streamlined offsets, such as the offset 16, on blanks such as that denoted by reference numeral 14, is generally denoted by reference numeral 18. The offset layout apparatus includes a base support generally denoted by reference numeral 20, which support includes a depending leg 22, a horizontally disposed leg 24 which normally extends under the surface of the table top 12, and by which the base support 20 is mounted to the table by means of the bolts 26. The base support 20 further includes a portion 28 which extends upwardly adjacent the edge of the table, and a horizontally disposed upper leg generally denoted by reference numeral 30, the top face of which lies in the same plane as the top face of the table top 12. The leg generally denoted by reference numeral 30 includes a plurality of apertures 32 therein, the apertures 32 being generally rectangular in configuration and leaving the spaced leg portions 34 therebetween.

A base bar, generally denoted by reference numeral 36, comprising a long flat bar 38, is attached at the edge of the layout table to base support at either end thereof by suitable attaching means which extend through the apertures 40. Thus, as will be observed the bar 38 is mounted on the upper horizontally disposed leg 30 of the base support 24 only at the ends thereof so as to allow sheet metal blanks such as blank 14 to he slid therebeneath, as will be appreciated by viewing FIGURE 2, for example. On one end of the bar 38 there are formed the cutout position marks 42, which marks are numbered consecutively, in pairs, divergent from a comm-on center post, not illustrated, and which are symmetrical about the center mark. As illustrated in FIGURE 3, the maximum value of the position marks is shown to be 48, but it will be appreciated, of course, that the length of the bar may be any desired length, the length in this case being 48 inches and the marks 42 are one-half inch apart. Thus the distance between the position marks 10 to the right and left of the centerline would appear to be ten inches. However, a joining allowance which is normally used in order to allow the top and bottom walls of the offset to be joined to the side offsets in order to form the duct, is added to the top and bottom walls. Since the Pittsburgh Lock Seam is almost universally employed for longitudinal seams and duct ports of this type, this allowance amounts to /8 of an inch. Further, since this allowance will be equally divided at the edges of the offsets, the distance from either of the position marks 10 to the centerline will be exactly five and three-sixteenths inches. The base bar 38 further includes a plurality of mounting studs 44 which protrude upwardly from the bar 38 and are spaced apart a predetermined distance in order to mount precalibrated bars thereon.

One such predetermined bar is illustrated in FIGURES 1-3, and is generally denoted by reference numeral 46. The calibrated bar 46 comprises an elongate flat bar 48 with apertures 50 therein, the apertures being so spaced so that there is only one position on the base bar mounting studs 44 on which any particular bar 48 may be positioned.

The calibrated bars 48 are further provided with a series of pattern apertures 52 spaced in a predetermined manner on each bar along the length thereof and adjacent the inner edge 54 thereof. When a calibrated bar 48 is in its allotted position on the base bar mounting studs 44, then each aperture 52 will be a predetermined distance from the centerline mark on the base bar 38. Each of these apertures 52 thus represents a center of curvature for an offset such as the offset 16, and each of the apertures 52 is labeled with a number which denotes the amount of offset, indicated in FIGURE 1 as the distance OS. Further, each calibrated bar 46 is labeled with a number which denotes the length L of the offset as denoted by the letter L in FIGURE 1. As an example, if it is desired to make an offset with a finished length which is to be 36 inches, the calibrated bar denoted by the numeral 36 is placed in the appropriate location on the positioning studs 44 of the base bar 36. This position will be the only position at which that particular calibrated bar will seat on the studs. At this time, a sheet metal blank 14 of appropriate width and length is placed on the upper surface of the table top 12 and moved into position by reference to the position marks 42 on the base bar 36. The position marks 42 correspond to the width W of the offset. Thus, if. an offset of width 41 inches, for example, is to be inscribed or marked on the meal sheet 14, the right-hand edge of the metal sheet would be moved into alignment with the positioning mark 41 on the upper face 39 of the base bar 36 adjacent the position marks 42.

It is desirable to be able to include a joining allowance directly to the length of the offset 16, such a joining allowance being indicated by the distance line Z in FIG- URE 1. It will be appreciated of course that the joining allowance occurs at each end of the offset. This joining allowance is necessary to connect the ends of the offset presently being cut to those sections of duct which precede and follow the offset sections as the ductwork is erected in place. In order to include such joining allowance distance Z directly to the offset 16, an adjustable back stop 56 is mounted on the base support 20 by the support and adjust rod 58. Thus, it will be observed in FIGURE 3, for example, that the adjustable back stop member 56 includes a mounting aperture 60 therein through which the rod 58 extends, the adjustable back stop member 58 being mounted on the rod 58 by the washers 62 and nut 64. Further, the adjustable back stop member includes a plurality of cutout portions 66 spaced along the upper edge 68 thereof leaving the upstanding leg portion 70 therebetween. The base bar 36 includes a plurality of cutouts 72 therein corresponding to the cutouts 32 in the leg 30 of base support 20, and thus, as will be appreciated by viewing FIGURES 2 and 3, when the base bar 36 is mounted on the leg 30, and the back stop 56 is mounted on the rod 58, the leg portions 70 will extend into the cutouts 32 and 72, the leg portions 34 of the legs 30 extending at the same time into the cutout 66. By referring to FIGURE 2 in particular, it will be observed that as the sheet metal blank 14 is moved inwardly toward the edge of the table 10, due to the floating mounting of the base bar 36 on the leg 30, the blank 14 will slide under the base bar until it contacts the leg portion 70 of the adjustable back stop 56 and is stopped thereby. Thus, in this fashion, a desired amount of joining allowance Z may be added to length L of the offset 16.

Of course, it is desirable to be able to adjust the position of the back stop 56 with respect to the edge of the table top 12, in order to be able to vary the desired joining allowance length Z. In this regard, the support and adjust rod 58 has a rack 74 mounted on the inboard end thereof, the rack 74 being slidable in a slide member 76 which is in turn bolted to the underside of the table top 12 by the bolts 78. It will be appreciated that the rack 74 slides in grooves in the slide member 76 perpendicular to the side of the table on which the base support 20 is mounted. In order to move the rack 74. within the slide 76, a rotatable shaft 80 is mounted in the mounting bracket 82 which is mounted on the underside of the table top 12, the rotatable shaft 80 including a pinion gear 84 thereon in normal meshing contact with the rack 74. The shaft 80 has a handle 84 at one end thereof, the handle being adjacent the lateral edge of the table top 12 and thus, when the handle 84 is turned, thereby turning the shaft 80, the rack 74 will be driven and moved longitudinally through the slide 76 thereby carrying the adjustable back stop 56 therewith in order to adjust the amount of joining allowance distance Z. It will be appreciated by viewing FIGURE 1 in particular, that a second support and adjust rod will be included at the left hand end of the table 10, and an assembly similar to that described immediately above, including a handle, rotatable rod, rack and slide will be included, whereby the position of the adjustable back stop 56 may be adjusted from either end of the table. It will be appreciated that the adjustable back stop need not extend the full length of the table. However, when it does, it is extremely important that the two support and adjust assemblies be linked by a single shaft which will assure the movement of both assemblies together thereby maintaining the back stop parallel to the edge of the base bar.

In order to measure the exact position of the adjustable back stop 56 with respect to the longitudinal edge of the table top 12 and thus obtain an exact joining allowance Z, a depth gauge generally indicated by reference numeral 86 is mounted on the support base 20. The depth gauge 86 includes a ruler 88 which extends through the generally rectangular aperture 90 in the leg 22, and is slidable therein, the ruler 88 including a mounting bracket 92 mounted in dependency therefrom as for example by the screws 94, the bracket 92 also being mounted on the adjustable back stop 56. An indicator member 96 is mounted on the leg 30 and includes a depending leg portion 98 which extends downwardly into close adjacency to the scale on the top face of the ruler 88. Thus, when the adjustable back stop 56 is moved in response to rotation of the handle 84 with respect to the longitudinal edge of the table top 12, the distance at which the back stop is positioned at any particular time with respect to the longitudinal axis of the table top will be able to be read directly on the scale of ruler 88, and in this manner, the exact amount of joining allowance distance Z may be quickly and easily set.

Referring now to FIGURES l, 2, 5 and 6, a marking compass generally denoted by reference numeral 100 will be observed. The marking compass 100 includes a pivot head generally denoted by reference numeral 102, which head includes a C clamp 104 and setscrew 106 for mounting the clamp on the rod 108 at one end thereof. The pivot head 102 includes a depending stud 110 the end of which is turned down to fit the center of curvature apertures 52 in calibrated bars 46. Further, the stud 110 is of such height as to allow the rod 108 to be maintained substantially horizontal to the metal sheet 14 throughout its length. A pair of marking heads 112 and 114 are mounted on the rod 108 at appropriate points thereon in order to mark the inner and outer edges of the offset 16 on the sheet 14 as the rod 108 is swung about the stud 110 of the pivot head 102. The outer marking head 112 includes a C-clamp body member 116 and setscrew 118 for attaching the body member 116 on the rod 108 as well as a generally conventional replaceable trammel point 120 for inscribing or marking the sheet 14. The inner marking head 114 includes the C-clamp body portion 122 and setscrew 124 for mounting the body portion 122 on the rod 108 and an adapter section 124 including the recess 126 therein and a replaceable carbide marking point 128 on the adapter section 124. The adapter section 124 with the recess 126 therein is necessitated in order to enable the point 128 to go beneath the overhanging calibrated bar 46 which may extend adjacent the left side of the offset being so marked out, depending of course, on the width of the offsets.

Thus, with reference to the above description, the use of the offset layout apparatus 18 should be readily appreciated. A sheet metal blank 14 is positioned on the table top 12 by aligning it with the appropriate position mark 42 on the base bar 36, depending upon the required offset width W. Then, an appropriate calibrated bar 46 is selected depending upon the required length L of the offset, the bar being positioned on the mounting studs 44 which extend upwardly from the upper surface 39 of the base bar 36. Of course, the positioning of the studs 44 as well as the apertures 50 in the calibrated bars makes it possible for any particular calibrated bar to be positioned at only one point on the base bar 36. At this time, the desired joining allowance distance Z is set on the adjustable back stop 56 by means of the rod 68, rack 74, slide 76, pinion gear 84 and rotatable shaft and handle 80 and 84. Then, the pivot head stud pin 110 is placed in the appropriate aperture 52 in the calibrated bar 46 depending upon the required amount of offset OS. Each of the holes, of course, represents a center of curvature for a particular amount of offset. With the stud 110 held in the calibrated bar aperture 52, which aperture constitutes a center of curvature for the offset 16, the marking heads 1-12 and 114 are adjusted such that each marking point is positioned along the edge of the base bar 36 at a distance apart corresponding to the width W of the offset, being so positioned at the position marks 42 corresponding to the width W of the offset. At this time,

the rod 108 is swung in order to mark or inscribe arcs in the blank 14, the arcs constituting one: half of the offset 16. With the compass set as it is, the blank 14 is reversed degrees on the table and repositioned against the adjustable back stop which, of course, will remain in its originally set position. At this time, the compass is again swung drawing the second half of the offset, this completing the offset outline. It will be appreciated that this whole procedure will take only a very few minutes, rather than the much longer time, up to 10-20 minutes required for the prior triangulation method mentioned above. At this time the mechanic has completed the use of the instant invention in laying out the offset and is ready to cut the blank.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling: within the scope of the invention as claimed.

What is claimed as new is as follows:

1. Apparatus for laying out and inscribing streamlined offsets or blanks comprising, means for receiving a blank in substantially horizontal position, means on said receiving means for positioning said blank on said receiving means in accordance with the desired width of the offset, means on said receiving means for mounting a calibrated rod member in accordance with the desired length of the offset, a marking compass, said calibrated rod member having means therein for rotatably receiving one end of said marking compass in accordance with the desired amount of offset, said marking compass having at least one marking head thereon for marking one edge of an offset on said blank as said marking compass is rotated in said rotatable receiving means.

2. The combination of claim 1 including first and second marking heads on said marking compass, an adapter means on one of said marking heads for enabling the marking compass to be used to inscribe a complete half offset on said blank.

3. The combination of claim 1 wherein said first named receiving means comprises an offset layout table having a substantially horizontal top surface, said positioning means comprising a supporting base member mounted adjacent one longitudinal edge of said top, a calibrated base bar mounted on said base support adjacent said lon- :gitudinal edge of said table top, said. base bar being mounted to receive said blank thereunder whereby said blank may be moved laterally outwardly of the edge of the table, and means on said base support for limiting the outward movement of said blank.

4. The combination of claim 3 wherein said limiting means comprises an adjustable back stop, a portion of said adjustable back stop extending upwardly into the plane defined by the top surface of said table top, said portion thereby comprising stop means, means for adjusting the position of said back stop with respect to said longitudinal edge, and means for indicating the position of said back stop with respect to said longitudinal edge.

5. Apparatus for laying out and inscribing offsets on blanks comprising, a supporting surface, means mounted longitudinally along said supporting surface for indicating the correct position of a blank on said supporting surface on the basis of the desired width of said offset, means mounted on said indicating means and extending longitudinally along said supporting surface for rotatably receiving an end of a marking compass therein, said receiving means comprising one of a plurality of different size calibrated rod members selected on the basis of the desired length of said offset, said rod members having calibrated apertures therein corresponding to the center of curvature of various size offsets, a marking compass adapted to be rotatably mounted at one end in one of said calibrated apertures in said rod member, said compass having at least one marking head thereon whereby a portion of one edge of an offset may be inscribed on said blank by rotating said compass.

6. The combination of claim 5 wherein said indicating means comprises a support bar attached to said supporting surface, calibrated bar means mounted on said support bar, said support bar and calibrated bar means defining a blank receiving recess therebetween for adding a joining allowance to the offset length, and means for adjusting the depth of said recess whereby said joining allowance may be varied.

No references cited.

LEONARD FORMAN, Primary Examiner.

H. N. HAROIAN, Assistant Examiner. 

1. APPARATUS FOR LAYING OUT AND INSCRIBING STREAMLINED OFFSETS OR BLANKS COMPRISING, MEANS FOR RECEIVING A BLANK IN SUBSTANTIALLY HORIZONTAL POSITION, MEANS ON SAID RECEIVING MEANS FOR POSITIONING SAID BLANK ON SAID RECEIVING MEANS IN ACCORDANCE WITH THE DESIRED WIDTH OF THE OFFSET, MEANS ON SAID RECEIVING MEANS FOR MOUNTING A CALIBRATED ROD MEMBER IN ACCORDANCE WITH THE DESIRED LENGTH OF THE OFFSET, A MARKING COMPASS, SAID CALIBRATED ROD MEMBER HAVING MEANS THEREIN FOR ROTATABLY RECEIVING ONE END OF SAID MARKING COMPASS IN ACCORDANCE WITH THE DESIRED AMOUNT OF OFFSET, SAID MARKING COMPASS HAVING AT LEAST ONE MARKING HEAD THEREON FOR MARKING ONE EDGE OF AN OFFSET ON SAID BLANK AS SAID MARKING COMPASS IS ROTATED IN SAID ROTATABLE RECEIVING MEANS. 